Parallel-ruler



(No Model.)

J. J. HAMILTON.

PARALLEL RULER.

No. 407,350. Patented July 23. 1889.

UNITED STATES PATENT OFFICE.

JOHN J. HAMILTON, OF ST. LOUIS, MISSOURI.

' PARALLEL-RULER.

SPECIFICATION forming part of Letters Patent No. 407,350, dated July 23,1889.

Application filed March 22, 1889. Serial No. 304,257- (No model.)

['0 all whom it may concern:

Be it known that 1, JOHN J. HAMILTON, a citizen of the United States,residing at St. Louis, Missouri, have invented certain new and usefulImprovements in Parallel-Rulers, of which the following is aspecification.

My invention relates to parallel-rulers; and it consists of theconstruction and arrangement of the parts thereof, to be hereinafterpointed out; and it further consists in providing one or both of theconnecting-links with 'a peculiar scale, by the use of which one mayeasily and rapidly and yet accurately set the rulers, so as to insurethat the lines to be ruled shall be at any desired distance apart.

That my invention may be the better understood, I have illustrated it inthe accompanying drawings, wherein Figure 1 is a face view of a rulerhaving my invention applied thereto. Fig. 2 is a similar view from theopposite side of the ruler. Fig. 3 is a cross-section on the line 3 3,Fig. 2, the parts being enlarged; and Fig. 4 is a face view of a rulerhaving its connecting-links jointed.

In the drawings, 1 designates a ruler, which may be of any usual orpreferred style, the one shown having one edge beveled and provided witha metallic strip 2 and with a scale 3 of inches and subdivisionsthereof.

To the ruler 1 a straight-edge bar or ruler4 is pivotally connected bythe links 5, which are by preference pivoted to the rear side or face ofthe ruler 1, these parts together'forming a parallel-ruler. One (andpreferably both) of the links 5 is provided with a graduated scale 6,the lines of which are adapted to be brought successively intoparallelism with a line on the ruler l, the line which I prefer beingthe beveled edge 7.

As will be seen from an examination of Fig. 2, the lines of thegraduation of the scale are not parallel with each, nor are they equaldistances apart; but they are so arranged that when the links 5 aremoved to carry the scale past the line 7 from any one graduation to thenext the rulers will approach or recede from each other a certaindetermined distance for each graduation, so that while the lines arefarther apart toward the outer ends of the links than they are nearertheir fulcrums,

still the bar 4 is moved an equal distance toward or from the edge 7 foreach and every graduation of the scale.

One link may be provided with a decimal or a'metrical scale and theother with a scale, which will gage the movements of the two rulers bysixteenths of an inch.

The links 5 are pivoted to the ruler 1 near the ends'thereof and thescales 6 placed along their inner edges.

The bar 4 is preferably of substantial V shape in cross-section, and isadapted to lie over the beveled edge of the ruler when the two arefolded together, in which position the whole may be used as an ordinaryruler or as a paper-cutter, the two parts of the bar 4 coming togetherand forming a sharp edge.

, When the ruler 1 is placed face down and flat in position for ruling,as shown in Fig. 2, the bar 4 is held with its inner straight-edge 8close to but above the paper, so that it may be moved over freshly-ruledlines without blurring them.

While my invention is adapted to be used asan ordinary parallel-ruler,its particular advantage lies in the ease with which a user can gage thedistance between the lines to be drawn and change the ruler from onegage to another without having to make measurements by means of thescale.

The invention is used in the following manner, supposing the scale to bea sixteenth-inch scale and the lines to be five-sixteenths of an inchapart. The links are first moved until the fifth line from the outer endof the scale is in line with the edge 7 of the ruler. The inner edge ofthe bar 4 is then placed directly above the line from which the one tobe ruled is to be five-sixteenths of an inch, when the desired line maybe ruled along the beveled edge 7 of the ruler 1. This operation isrepeated as often as may be desirable, the last line ruled being in eachcase the base-line for the next succeeding. It will thus be seen that bymeans of the scales 6 parallel lines may be accurately ruled the desireddistance apart without having to measure for each line, or even tomeasure between the first two lines, and that the distances between thedifferent lines may be varied by simply moving the links 5, so as tobring different marks of the scale in proper position relatively to thefixed line on the ruler.

In Fig. l I have shown a ruler the connecting-links whereof are formedof two parts a and I), jointed together at 0, so that when the tworulers 1. and lare closed together one will not project beyond the otherat the end, as is the case when the links are rigid.

\Vhen jointed links are employed, devices of some style for holding thetwo parts of the links in line with each other must be employed, so thatwhen the ruler is being used the links may operate as though each wereof one rigid piece. A simple device of this character is that shown inFig. 4, where 9 is a slide seated in a groove 10 in the part a of thelink, and adapted, where the two parts of the link are brought :intoline with each other, to be slid across the line of division between thetwo parts and to lie partly in the groove 10 and partly in a groove 11in the part b of the link, and thus hold the parts a and I) rigidly inline with each other.

Without limiting myself to the precise construction and arrangement ofparts shown, I clain1 l. A parallel-ruler having one or each of itspivoted connecting-links provided with a graduated scale adapted toswing adjacent to a fixed line on the ruler, substantially as set forth.

A parallel-ruler having one of its pivoted connecting-links providedwith a scale the graduating lines of which are not parallel and are atdifferent distances apart, and a fixed line on the ruler past which thesaid lines of the scale are moved, substantially as and for the purposeset forth.

A parallel-ruler having the two rulers connected by links pivoted nearthe outer ends of the rulers, and one or both provided along their inneredges with a scale 0, substantially as set forth.

4. The combination of the ruler having a beveled edge, the V-shapedstraight-edge bar or ruler adapted to lie over the beveled edge of theruler, and the connecting-links between the ruler and bar, substantiallyas set forth.

5. A parallel-ruler consisting of a rulerl, having a ruling-edge, thecomieeting-lin ks, and another ruler or bar having a straightedge 8, andthe last said ruler or bar being held by the said links'above thesurface to be ruled with its edge 8 close thereto, but not in contacttherewith, substantially as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN J. HAMILTON.

\Vitnesses:

J AMES W EST, F. L. \VISSMAN.

